One representative ceramic electronic component is, for example, a multilayer ceramic capacitor having a structure as shown in FIG. 5.
As shown in FIG. 5, this multilayer ceramic capacitor has a structure including a stack of ceramic layers (ceramic body) 60 in which a plurality of internal electrodes 52 (52a, 52b) are stacked in layers with a ceramic layer 51 as a dielectric layer interposed there between, and external electrodes 54 (54a, 54b) arranged on opposite end surfaces 53a, 53b of ceramic body 60 which are electrically connected to internal electrodes 52 (52a, 52b).
Note that each of external electrodes 54 (54a, 54b) often has a structure in which a Ni-plating film layer is formed over a surface of an external electrode main body made of Cu, for example, and a Sn-plating film layer is additionally formed over a surface of the Ni-plating film layer.
In manufacturing this multilayer ceramic capacitor, external electrodes 54 (54a, 54b) are generally formed using a method in which a conductive paste is applied to the opposite end surfaces of the stack of ceramic layers (ceramic body), and then fired.
As such a conductive paste for use in forming the external electrodes, a conductive paste (conductor paste) has been proposed in which glass frit and at least one or more conductive materials selected from Ag, Au, Cu, Ni, Pd, and Pt, for example, are dispersed in a vehicle, wherein the glass frit, calculated as oxides, is composed of SrO: 40.0 to 70.0 wt %; B2O3: 15.0 to 30.0 wt %; Al2O3: 10.0 to 20.0 wt %; SiO2: 3.0 to 20.0 wt %; and MnO: 0 to 20.0 wt % (see Japanese Patent Laying-Open No. 9-55118).
Japanese Patent Laying-Open No. 9-55118 also discloses a multilayer ceramic capacitor including external electrodes formed with the above-described conductive paste.
Furthermore, Japanese Patent Laying-Open No. 9-55118 describes that the use of the above-described conductive paste allows the formation of external electrodes having excellent tensile strength and bending strength, leading to a multilayer ceramic capacitor having high mounting reliability.
In the conductive paste according to Japanese Patent Laying-Open No. 9-55118, the bending strength of the external electrodes is improved by defining the glass frit to control the coefficient of linear expansion in the glass phase and the reaction phase after baking, thereby reducing a residual stress caused by the resulting external electrodes.
Indeed, in order to enhance mechanical properties of the multilayer ceramic capacitor, it would be effective to define the glass frit for use in the conductive paste used for forming the external electrodes, so as to control the coefficient of linear expansion in the glass phase and the reaction phase after baking.
However, the stress caused by the external electrodes cannot necessarily be sufficiently reduced by merely controlling the coefficient of linear expansion in the glass phase and the reaction phase, and therefore, there is room for improvement under such circumstances.